DESIGN AND CONSTRUCTION OF AN INTELLIGENT 250 VOLTS BATTERY CHARGER WITH MICRO PROCESSOR USING SEVEN SEGMENT DISPLAY
CHAPTER ONE
INTRODUCTION
WHAT IS A BATTERY CHARGER: A battery charger is a device used to put energy into a secondary cell or rechargeable battery. By forcing on electric current through it.
The charge current depends upon the technology and capacity of the battery being charged. For example, the current that should be applied to recharge a 12v car battery will be very different from the current for a mobile phone battery.
WHAT IS AN INTELLIGENT BATTERY CHARGER: This is a battery charger whose output current depends upon the battery’s state. An intelligent charger may monitor the battery’s voltage, temperature and/ or time under charge to determine the optimum charge current at that instant. Charging is terminated when a combination of the voltage, temperature and/or time indicates that the battery is fully charged.
OTHER TYPE OF BATTERY CHARGERS
1. SIMPLE BATTERY CHARGER: A simple charger works by connecting a constant dc power source to the battery being charged. A simple charger does not alter its output based on time or the charge on the battery. This simplicity means that a simple charger is inexpensive but there is a trade off in quality.
2. TRICKLE BATTERY CHARGER: A trickle charger is a kind of simple charger that charges the battery slowly, at the self-discharge rate. A trickle charger is the slowest kind of battery charger.
3. TIMER-BASED BATTERY CHARGER: The output of timer charger is terminated after a predetermined time. Timer chargers were the most common type for high-capacity Ni-Cd cells in the late 1990s
4. FAST BATTERY CHARGER: fast chargers make use of control circuitry in the batteries being charged to rapidly charge the batteries without damaging the cells element. Most such chargers have a cooling fan to help keep the temperature of the cells under control.
5. PULSE BATTERY CHARGER: some charger use pulse technology in which a pulse is fed to the battery. This DC pulse has a strictly controlled rise time, pulse width, pulse repetitive rate (frequency) and amplitude. This technology is used to work with any size, voltage, capacity or chemistry of batteries including automotive and valve-regulated batteries. .
6. INDUCTIVE BATTERY CHARGER: Inductive battery chargers use electromagnetic induction to charge batteries. A charging station sends electromagnetic energy through inductive coupling to an electrical device which stores the energy in the batteries.
7. USB-BASED BATTERY CHARGER: Since the universal serial bus specification provides for a five-volt power supply, it is possible to use a USB cable as a power source for recharging batteries.